/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.dotmarketing.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.BitSet;



/**
 *
 * This class is very similar to the java.net.URLEncoder class.
 * Unfortunately, with java.net.URLEncoder there is no way to specify to the 
 * java.net.URLEncoder which characters should NOT be encoded.
 * This code was moved from DefaultServlet.java
 * @author Craig R. McClanahan
 * @author Remy Maucherat
 */

public class URLEncoder {

    protected static final char[] hexadecimal = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
    //Array containing the safe characters set.
    protected BitSet safeCharacters = new BitSet(256);

    public URLEncoder() {
        for (char i = 'a'; i <= 'z'; i++) {
            addSafeCharacter(i);
        }

        for (char i = 'A'; i <= 'Z'; i++) {
            addSafeCharacter(i);
        }

        for (char i = '0'; i <= '9'; i++) {
            addSafeCharacter(i);
        }
    }



    public void addSafeCharacter( char c ) {

	safeCharacters.set( c );

    }



    public String encode( String path ) {

        int maxBytesPerChar = 10;

        int caseDiff = ('a' - 'A');

        StringBuffer rewrittenPath = new StringBuffer(path.length());

        ByteArrayOutputStream buf = new ByteArrayOutputStream(maxBytesPerChar);

        OutputStreamWriter writer = null;

        try {

            writer = new OutputStreamWriter(buf, "UTF8");

        } catch (Exception e) {

            e.printStackTrace();

            writer = new OutputStreamWriter(buf);

        }



        for (int i = 0; i < path.length(); i++) {

            int c = (int) path.charAt(i);

            if (safeCharacters.get(c)) {

                rewrittenPath.append((char)c);

            } else {

                // convert to external encoding before hex conversion

                try {

                    writer.write((char)c);

                    writer.flush();

                } catch(IOException e) {

                    buf.reset();

                    continue;

                }

                byte[] ba = buf.toByteArray();

                for (int j = 0; j < ba.length; j++) {

                    // Converting each byte in the buffer

                    byte toEncode = ba[j];

                    rewrittenPath.append('%');

                    int low = (int) (toEncode & 0x0f);

                    int high = (int) ((toEncode & 0xf0) >> 4);

                    rewrittenPath.append(hexadecimal[high]);

                    rewrittenPath.append(hexadecimal[low]);

                }

                buf.reset();

            }

        }

        return rewrittenPath.toString();

    }

}

